January 21, 2008 - Pfizer Changes Chantix Label.. Pfizer today (Friday, 1/18/2008) updated the CHANTIX label in the U.S. to include a warning that patients who are attempting to quit smoking with CHANTIX should be observed for serious neuropsychiatric symptoms, including changes in behavior, agitation, depressed mood, suicidal ideation and suicidal behavior. The warning comes nearly five months after a CBS 11 (Dallas - Ft.Worth) investigation uncovered thousands of reports of adverse reactions to the drug. In November, the Food & Drug Administration announced it was reviewing the safety of Chantix, after receiving similar reports to the ones uncovered by CBS 11. Chantix is marketed as Champix in Europe and Australia. In December, CBS 11 reported a similar warning to the one announced today in the United States would accompany packages of Champix in Australia. In the United Kingdom, government medical officials continue to investigate the safety of Champix. In December, CBS 11 reported the number of people in the United Kingdom reporting suicidal thoughts while using the drug doubled in just 60 days. Related news brief: Chantix Reports of Suicidal Thoughts and Aggressive and Erratic Behavior..